/*!	 valuenode_derivative.h
**	 Header file for implementation of the "Derivative" valuenode conversion.
**
**	Copyright (c) 2014 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifndef __SYNFIG_VALUENODE_DERIVATIVE_H
#define __SYNFIG_VALUENODE_DERIVATIVE_H

#include <synfig/valuenode.h>

namespace synfig
{

// Class ValueNode_Derivative
// Implementation of a derivateive based on finite diferences
// See: http:// en.wikipedia.org/wiki/Finite_difference
// and http:// en.wikipedia.org/wiki/Finite_difference_coefficients

class ValueNode_Derivative : public LinkableValueNode
{

    ValueNode::RHandle link_;         // Value Node whom is calculated the derivative
    ValueNode::RHandle interval_;     // Size of the interval to calculate the finite differences
    ValueNode::RHandle accuracy_;     // Accuracy order
    ValueNode::RHandle order_;        // First or Second order derivative

    ValueNode_Derivative(const ValueBase &value);

public:

    enum Accuracy {
        ROUGH     = 0,
        NORMAL    = 1,
        FINE      = 2,
        EXTREME   = 3
    };
    enum Order {
        FIRST     = 0,
        SECOND    = 1
    };
    typedef etl::handle<ValueNode_Derivative> Handle;
    typedef etl::handle<const ValueNode_Derivative> ConstHandle;

    virtual ValueBase operator()(Time t)const;

    virtual ~ValueNode_Derivative();

    virtual String get_name()const;
    virtual String get_local_name()const;

    virtual ValueNode::LooseHandle get_link_vfunc(int i)const;

protected:
    LinkableValueNode* create_new()const;
    virtual bool set_link_vfunc(int i, ValueNode::Handle x);

public:
    using synfig::LinkableValueNode::get_link_vfunc;

    using synfig::LinkableValueNode::set_link_vfunc;
    static bool check_type(Type &type);
    static ValueNode_Derivative* create(const ValueBase &x);
    virtual Vocab get_children_vocab_vfunc()const;
}; // END of class ValueNode_Derivative

}; // END of namespace synfig

#endif